//
//  WelcomeViewController.swift
//  WeiBo_test
//
//  Created by 张leslie45 on 16/1/18.
//  Copyright © 2016年 张leslie45. All rights reserved.
//

import UIKit
import SnapKit
import SDWebImage

class WelcomeViewController: UIViewController {

    override func loadView() {
        view = backImageView
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        //添加子视图
        setupUI()
    }
    
    //动画效果不推荐在viewDidLoad / loadView中执行动画
    //推荐在ViewDidAppear中执行动画效果
    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
//        //执行动画
        showAnimation()
    }
   
    private func setupUI(){
      self.view.addSubview(headImageView)
      self.view.addSubview(welcomeLabel)
      //设置约束
        headImageView.snp_makeConstraints { (make) -> Void in
            make.bottom.equalTo(self.view.snp_bottom).offset(-160)
            make.centerX.equalTo(self.view.snp_centerX)
            make.size.equalTo(CGSize(width: 90, height: 90))
        }
        
        welcomeLabel.snp_makeConstraints { (make) -> Void in
            make.top.equalTo(headImageView.snp_bottom).offset(10)
            make.centerX.equalTo(headImageView.snp_centerX)
        }
        
        //头像的圆角设置
        headImageView.layer.cornerRadius = 45
        headImageView.layer.masksToBounds = true
        
        //隐藏方案
        welcomeLabel.alpha = 0
        
        //显示用户头像
        headImageView.sd_setImageWithURL(UserAccountViewModel().headImageURL, placeholderImage: UIImage(named: "avatar_default_big"))
    }
    
     //MARK:显示动画效果
    private func showAnimation(){
        /*
        在动画闭包中修改 头像的底部的约束
        更新某一条已经添加过的约束,如果该约束不存在 会自动添加该约束
        1.usingSpringWithDamping:弹簧系数  0.1- 1 越小 越弹
        2.initialSpringVelocity 加速度
        options:动画可选项 OC按位枚举 swift:数组
        弹簧系数设置准则(弹簧系数 * 10 = 加速度)
        使用自动布局 + 动画闭包 =====>强制刷新新视图
        */
         let offset = -UIScreen.mainScreen().bounds.height + 160
         self.headImageView.snp_updateConstraints { (make) -> Void in
            make.bottom.equalTo(self.view.snp_bottom).offset(offset)
        }
        UIView.animateWithDuration(1.5, delay: 0, usingSpringWithDamping: 0.98, initialSpringVelocity: 9.8, options: [], animations: { () -> Void in
            //放在代码块中执行,并且需要在修改约束之后调用
            self.view.layoutIfNeeded()
            }) { (_) -> Void in
              //显示方案
                UIView.animateWithDuration(0.6, animations: { () -> Void in
                    self.welcomeLabel.alpha = 1.0
                    }, completion: { (_) -> Void in
                        print("OK")
                     //发出显示首页的通知
                      NSNotificationCenter.defaultCenter().postNotificationName(WBSwiftRootVC, object: nil)
                        print("come here")
                })
        }
    
    }
    
    
 
    //懒加载子视图
    private lazy var backImageView:UIImageView = UIImageView(image: UIImage(named: "ad_background"))
    //用户头像
    private lazy var headImageView:UIImageView = UIImageView(image: UIImage(named: ""))
    private lazy var welcomeLabel:UILabel = UILabel(title: (UserAccountViewModel().userName ?? "") + "欢迎归来", fontSize: 18, color: UIColor.darkGrayColor())
}
